A 20 year old woman with DM was admitted to the hospital in a semiconscious state with fever, nausea and vomiting. Her breath smelled of acetone. A urine sample was strongly positive for ketone bodies. Which one of the following is correct about this woman?
A. A blood glucose test will probably show that he blood glucose level is much lower than 80 mg/dL.
B. An injection of insulin will decrease her ketone body production.
C. She could be given a glucose infusion so she will regain consciousness.
D. Glucagon should be administered to stimulate gluconeogenesis in the liver.
E. The acetone was produced by decarboxylation pf the ketone body beta-hydroxybutyrate.
B. The acetone on the women's breath (which is produced by decarboxylation of acetoacetate; this E incorrect) and ketones in her urine indicate that she is in diabetic ketoacidosis. This is caused by low insulin levels, so her blood glucose levels are high because the glucose is not being taken up by the peripheral tissues (thus A and C incorrect). An insulin injection will reduce her blood glucose levels and decrease he release of fatty acids from adipose triglycerides. Consequently, ketone body production will decrease. Glucagon injections would just exacerbate the woman's current condition (thus D incorrect).
A woman was told by her MD to go on a low-fat feet. She decoded to continue to consume the same number of calories by increasing her carbohydrate intake while decreasing her fat intake. Which of the following lipoprotein levels would be decreased as a consequence of her diet?
D. Chylomicrons are blood lipoproteins produced from dietary fat. VLDL is produced mainly from dietary carbohydrate. IDL and LDL are produced from VLDL. HDL does not transport triacylglycerol to the tissues.
Assume that an individual has been eating excess calories daily such that he will gain weight. Under which of the following conditions will the person gain weight most rapidly?
A. If all the excess calories are due to carbohydrate
B. If all the excess calories are due to triacylglycerol
C. If all the excess calories are split 50/50% between carbs and triacylglycerols
D. if all excess calories are split 25/75% between carbs and triacylglycerols
E. It makes no difference what form the excess calories are in.
B. all the excess calories are derived from fat as opposed to carbohydrates.
A chronic alcoholic has been admitted to the hospital because of a severe hypoglycemic episode brought about by excessive alcohol consumption for the past 5 days. A blood lipid analysis indicates much higher than expected VLDL levels. The elevated VLDL is attributable to what underlying cause?
A. Alcohol-induced inhibition of lipoprotein lipase
B. Elevated NADH levels in the liver.
C. Alcohol-indced transcription of the app B-100 gene
D. NADH activation of phosphoenolpyruvate carboxykinase
E. Acetaldehyde induction of enzymes on the endoplasmic reticulum
B. Metabolism of ethanol leads to production of NADH in the liver, which will inhibit fatty acid oxidation in the liver. Because the patient has not eaten for 5 days, the insulin/glucagon ratio is low, hormone-sensitive lipase is activated, and fatty acids are being released by the adipocyte and taken up by the muscle and liver. However, because the liver NADH levels are high as a result of ethanol metabolism, the fatty acids received from the adipocyte are repackaged into triacylglycerol (the high NADH promotes the conversion of dihydroxyacetone phosphate to glycerol 3-phosphate as well) and secreted from the liver in the form of VLDL. None of he other answers is a correct statement.
Certain patients with abetalipoproteinemia frequently have difficulty maintaining blood volume; their blood has trouble clotting. This symptoms is attributable to what?
A. Inability to produce chylomicrons.
B. Inability to produce VLDL
C. Inability to synthesize clotting factors
D. inability to synthesize fatty acids
E. inability to absorb short-chain fatty acids
A. The clotting problems are caused by a lack of vitamin k, a lipid-soluble vitamin. Vitamin k is absorbed from the diet in mixed micelles and packaged with chylomicrons for delivery to the other tissues. Individuals with abetalipoproteinanemia lack the microsomal triglyceride transfer protein and cannot produce chylomicrons effectively, thus vitamin k deficiency can result. Such patients cannot produce VLDL, but lipid-soluble vitamin distribution does not depend on VLDL particles, only on chylomicrons. The other answers are all incorrect statements.
-A tumor of the pancreas leading to excessive episodic insulin secretion, usually coupled with weight gain to avoid hypoglycemia.